Means for controlling the tension in strips of flexible material while being drawn from coils or rolls



Fan 30, 12 34. BEAVER AL 1,944,916

EANS FOR CONTROLLING THE TENSION IN STRIPS OF FLEXIBLE MATERIAL WHILE BEING DRAWN FROM GOILS OR ROLLS Filed Feb. 25, 1932 SSheets-Sheet l 1 Fzgl.

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/? TTOR/VEVY Ja 30, 193 c. J. BEAVER ET AL 1,944,916

MEANS F0 0 LLING THE TENSION IN STRIPS OF FLEXIBLE OILS OR ROLLS MATE L LE BEING DRAWN FROM C Filed Feb. 25, 1932 I5 Sheets-Sheet 2 Jan. 30, 1934. c. J BEAVER AL 1,944,916

CONTROLLING THE TENSIO N STRIPS OF FLEXIBLE ILS OR ROLLS MEANS F MAT AL WHILE BEING DRAWN FROM CO Filed Feb. 25, 1932 3 Sheets-Sheet 5 24 vm 23 20 i F lg]. l 59 25 MIKE/10v? M,

THE/K OTTOKWEYS ber.

Patented Jan. 30, 1934 UNITED STATES PATENT OFFICE Charles James Beaver and Thomas James Fairfield, Bowdon, and Frank Smith, Stretford,

England Application February 25, 1932, Serial No. 595,210, and in Great Britain March 31, 1931 6 Claims.

This invention deals with arrangements for controlling the tension exerted on flexible material, such as paper or fabric, which is being drawn on in the form of strip or sheet from a coil or roll. The arrangement is of the known kind, of which an example is described in the specification of United States Patent No. 1,849,383, in which the value of the frictional retarding eifect applied to the coil or its carrier (which elfect determines m the tension of the material being drawn off) is adjusted continuously from its maximum value downwards as the size of the coil decreases with the object of maintaining an approximately constant tension in the material. In the type in question the adjustment is brought about by gearing driven by the coil holder, driving a member by which the variation in the pressure exerted by a spring on a brake is adjusted. By this means the value of the frictional retarding force applied 5 by the spring is co-ordinated with the number of revolutions made by the coil and the tension control mechanism is closely associated with the coil holder so that the two form a single unit. In this way the arrangement is made particularly applicable to the conditions in machines for lapping paper, tape or other material on a conductor in building up the insulation of an electric cable. In such cases there are usually a number of coil holders arranged close together and each requiring independent adjustment of the tension. In many cases also the lapping is eifected by rotating the coil holders round the cable. All these conditions can be provided for by the unit type of arrangement.

In accordance with the present invention we adopt a type of drive, between the coil holder and the spring pressure adjusting member, which is adapted for providing several ratios of gearing. These several ratios are obtained by mounting a number of trains of gearing of different ratios on carriers between a rotary driver and a driven wheel and arranging the carriers so that they can be moved to bring any one of the trains into action to connect the driver and the driven mem- This gives us the advantage of being able to provide accurate adjustment to suit a number of different thicknesses of strip.

To enable the invention to be more fully understood, an arrangement for controlling the tension '5 in strip material being withdrawn from a'single coil mounted on a coil holder and in which provision is made to drive in accordance with the present invention the spring pressure controlling member at four different speeds, is illustrated in the accompanying drawings wherein:--

Figure l is a sectional view of the coil holder mounting and tension controlling arrangement,

Figure 2 is a diagrammatic end elevation of the transmission gearings,

Figure 3 is a sectional elevation taken on the line AA in Figure 1 of the arrangement illustrated therein,

Figure 4 is a fragmental section of a modified form of the arrangement,

Figure 5 is an end elevation of the arrangement shewn in Figure 4 but having the screwed cap and wedging member removed,

Figure 6 is a view on a larger scale of the end of the spindle, the two part nut fitting thereon, and the wedge member,

Figure '7 is a frag-mental section of a form of the coil holder mounting and tension controlling arrangement which is provided with an interlocking control device, and

Figure 8 is a sectional end elevation of the part of the arrangement shown in Figure 7 but having portions thereto removed in order to show the interlocking device more clearly.

Before proceeding to describe the automatic part of the tension controlling arrangement illustrated in Figures 1, 2 and 3 of the drawings, a brief description of the form of coil holder mounting and braking will be given. This form of mounting and braking is similar to that set out in the specification of British Patent No. 177731. In this type of arrangement the coil 1 of flexible strip material, closely wound on a centre 2 and held by plates 3 and 4, is so mounted on one end of a carrier spindle 5 that it cannot move axially or angularly relative to the spindle which is rotatably supported in a bearing member 9 secured in the case where the coil holder rotates round a cable, to a lapping head. The means employed to limit the relative axial movement between the spindle 5 and bearing member 9 also serves as the frictional retarding means. To the plate 4 is secured a plate 7 carrying a friction disc 6 which is in contact with one side of a second disc 8 fixed to the bearing member 9. These plates 7 and 4 are secured on the spindle 5 by a key 11 which also serves to constrain a third disc 10, located on the opposite side of the disc 8, to rotate with the spindle. The disc 10 is, however, permitted a certain axial movement along the spindle 5. Between the disc 10 and the fixed disc 8 and secured to the former is a second friction disc 12. Behind the disc 10 is a helical spring 13 surrounding the spindle 5 and to the rear of this spring is the spring pressure adjusting member consisting of a sleeve 14 forming a nut 15 at its rear end, working on a thread on the spindle. Since the one part of the coil holder is fixed to the spindle by means of the key 11 and by the plate '7 abutting the shoulder 17 on the spindle and the other part by the member 36, the action of the spring. 13 is to press the friction lining 6 of the first disc 7 and that of the third disc 10 against opposite sides of the second disc 8, the value of the pressure depending upon the adjustment of the spring 13 which is determined by the position of the nut 15.

An example of the way in which the present invention is carried into efiect will now be described with reference to the drawings. The rotary driver and the driven wheel are arranged concentrically with each other. The former consists of a second sleeve 19, arranged concentrically about the first sleeve 14 and the spring 13, rotatably supported in the bearing 9, and so connected at its front end with the disc 10 by set-screws that it is driven by the spindle 5. The rear end of this driver is enlarged and formed with a concentric ring of internal teeth 21. The driven wheel consists of a ring of teeth 18 on the periphery of the sleeve 14 adjacent the nut 15. The pitch of the teeth on these two rings need not necessarily be the same. In cases where trains of gearing consisting of three or more wheels are used, a difference in pitch of the teeth on these rings may be advantageous in permitting the use of wheel trains of better proportion. The bearing member 9 is provided with a rearward extension 22 forming a casing for the enlarged end of the sleeve 19. A disc 23 is secured by set screws to the enlarged end 22 and completes the enclosure for the sleeve 19. Four trains of gearing for coupling the driver and driven wheel are mounted on four carriers 24 supported on the inner face of the disc 23. Each carrier 24 consists of a plate, on one side of which projects a stub axle 31 which is rotatably supported in a bearing in the disc 23 and projects outwardly beyond this disc to carry a knob 32 and on the opposite side of which project two or more spindles which each carry one or more gear wheels 26, the number being dependent upon the number and disposition of the wheels constituting the train. Four types of gearing trains 27, 28, 29 and 30, any one of which may be employed, are shown diagrammatically in Figure 2, the train 27, which is employed for resetting purposes as hereinafter described, being shewn in mesh with the rings of teeth 18 and 21, the other three trains 28, 29 and so being entirely out of mesh with these rings. Each train is brought into engagement by an angular movement of the axle supporting its carrier 24, a pointer 33 indicating whether the train is in or out of engagement with the two rings of teeth. Each train of gearing is maintained in one of its two positions by a pin 34 entering one of two holes 35 in the disc 23.

If it is preferred, an interlocking control device to ensure that only one of the trains can be operative at any one time may be incorporated.

In the example of a device of this kind shown in Figures 7 and 8 of the drawings, all the trains of gearing are normally held out of engagement with the rings of teeth 18 and 21 by means of helical springs 59 encircling the projecting portion of each stub axle 3 1. Each of these springs normally maintains a crank 58 on the end of the stub axle 31 tight against a pin 66 projecting from the disc 23. In this position of the crank, the

. train is disengaged. A sleeve 56 rotatably positioned on the nut 15 has on its peripheral surface a single cam 5'? adapted as the sleeve is rotated to engage each crank in turn and rotate it against the action of its spring 59 through an angle of about 90". As the cam leaves the crank, the stub axle is returned to the disengaged position by its spring. To maintain any one train of gearing in engagement the sleeve is adapted to be rotatably locked in any one of the four positions in which the cam is efiective, by the insertion of a pin 61 in one of four appropriately placed holes 63 in the disc 23, the pin 61 being held in position by a spring 62 acting against a collar 64 integral with or attached to the rod 61. A dust cover 65 is secured at one end to the sleeve 56 and at the other end has a flange running in a circular groove formed by a ring 66 secured to the disc 23. This serves to prevent the sleeve 56 changing its longitudinal position as the nut 15 moves along the threaded spindle.

As material is withdrawn from the roll the value of the force exerted by the spring must be reduced. Since in the type of arrangement illustrated, the spindle 5 rotates with the coil, it follows that the driven wheel actuating the spring pressure adjusting member, that is the nut 15, must be rotated in the same direction as and at a speed either slightly less or, in excess of that of the spindle, depending upon the direction of rotation of the coil and whether the screw thread 16 is left or right handed, so that x the nut is slowly moved toward the threaded end of the spindle 5. In coil supporting arrangements of the type described in United States Patent No. 1,849,383, the carrier spindle 5 does not rotate about its own axis. As a result, the driven member actuating the spring pressure adjusting member must be rotated at a very slow speed compared with that of the rotary driver. In this case each train of gearing may comprise two'worm reduction gears in series. Since, in the course of operation the ring of teeth 18 attached to the nut 15 will move outwards relatively to the disc 23 carrying the trains of gearing, the teeth of this ring are made of greater width than the teeth of the wheels of the trains of gearing which engage with it so as to maintain contact during all axial positions of the sleeve 14 on the spindle 5.

In both the fixed and rotating spindle types of arrangement the functions of the inner and outer rings of teeth may be transposed, the outer ring being attached to the spring pressure adjusting member and the inner being driven by the coil holder.

When the material has been removed from the coil, the outer disc 3, which is normally held in position by the sleeve 36 and the spring 37 which enters an appropriate recess in the spindle 5, is removed, thus permitting the empty centre 2 to be replaced by one carrying a new coil, the disc 3 being subsequently replaced. After placing a new coil in position it is necessary to take back the sleeve 14 to its starting position on the spindle 5. To do this the wheel train which has been employed to effect the rotation of this sleeve is brought into its inoperative position and the sleeve 14 may then be brought back by rotating it in the appropriate direction on the spindle 5. If

it is desired, one of the trains of gearing may train 2'7, when'brought intoits operative position, enables the sleeve 14 to be very quickly reset by rotating the spindle 5 by hand. The part 'ofthe sleeve forming the nut 15 and the threaded endof the spindle 16 preferably project beyond the disc 23 so that by'providing a scale 38 affixed to this disc the correct initial setting of the sleeve 14 may be readily determined.

In Figures 4, 5 and 6 is shewn an alternative arrangement which facilitates rapid longitudinal movement of the sleeve 14 and the resetting of the spring 13. In this case the nut 15 is not made integral with the sleeve 14 as shewn in Figure 1 but has the form of a split nut consisting of two parts 40 and 41. The two parts are contained in a bushing 43 positioned in the enlarged end 42 of the sleeve 14. Two internal walls of this bushing 43 are plane, opposite to and parallel with each other, and the other two walls are semi-cylindrical. The radius of the latter walls is made approximately equal to that of the peripheral surface of the nut. The height of the flat walls is made not less than an amount sufficient to permit the two parts of the nut to be separated so that the threads of the nut are withdrawn clear of the threads on the spindle. To reduce this distance the side parts of the nut are removed as shown at 44. Normally, the two parts of the nut are pressed together by four helical springs 45 partly housed in recesses 47 in the nut and recesses 48 in the bushing 43. The bushing 43 and both parts 40 and 41 of the nut are axially and angularly positioned relative to the sleeve 14 by two pins 49 screwed into the part 42 and passing through holes in the sleeve and entering recesses 50 in the nut. To separate the two parts of the nut, a collar 51, slidably positioned on the screwed end of the spindle 5 and carrying on diametrically opposite sides of this spindle two wedge pieces 52, is moved towards the split nut so that each wedge piece enters a V slot 53 formed by cutting the adjacent face of the nut symmetrically on each side of the plane of joint of the two nut parts. The collar 51 is conveniently moved towards the nut by rotation of a plug member 54 screwing in the enlarged end 42, disengagement of this plug member being prevented by a stop 55. Preferably the thread on the inner surface of the member 42 and the thread on the member 54 are of course pitch or are multiple threads so that a small rotation of the member 54 is sufficient to separate the two parts 40 and 41 to enable the sleeve 14 to be moved axially along so as to effect resetting of the spring 13 without any or without considerable rotation of the sleeve 14 being necessary.

It will be understood that whilst an embodiment of the invention has been described in considerable detail, this description has been given for illustrative purposes only and not with the intention of indicating that the invention is limited to the details there set forth.

What we claim as our invention and desire to secure by Letters Patent 'is:-

l. A co l holder and automatic tension control mechanism combined in a unit comprising the coil holder, a spindle on which the said coil holder is mounted, a brake acting on the coil holder, a spring exerting force on the brake, an adjustable rotary member controlling the spring, a rotary driver connected with the coil holder, a driven member connected with the said adjustable rotary member, at least two trains of gearing of different ratios and means for supporting each train and providing for such trainbeing moved into engagement with the driver and driven member as required.

2. A coil holder and automatic tension control mechanism combined in-a unit, comprising the coil holder, a spindle on which the said coil holder is mounted, a brake acting on the coil holder, a spring exerting force on the brake, an adjustable rotary member controlling the spring, two concentric toothed rings, one driven by the coil holder and the other attached to the said adjustable rotary member, at least two trains of wheels of different ratios, and means for supporting each train and providing for such train being moved into engagement with the concentric toothed rings as required.

3. A coil holder and automatic tension control mechanism combined in a unit; comprising a bearing, a spindle and two sleeves all concentrically and rotatably supported in the bearing, a coil holder mounted on the spindle, a brake acting on the coil holder, a spring exerting force on the brake, a screw thread on one end of the spindle, a nut working on the screw thread and controlling the spring and attached to the inner of the two sleeves, an externally toothed wheel mounted on the said inner sleeve, an internally toothed wheel concentric with the externally toothed wheel and attached to the outer of the two sleeves which is constrained to rotate with the spindle, a train of gearing, and means for supporting said train and providing for it being moved into engagement with the toothed wheels as required.

4. A coil holder and automatic tension control mechanism combined in a unit, compris ng a iember supporting the unit, the coil holder, a brake acting on the coil holder, a spring exerting force on the brake, a screw threaded member and a nut working thereon and controlling the spring, two concentric toothed rings, one driven by the coil holder and the other attached to the nut, a disc secured to the supporting member, at least two carriers adjustably mounted on the disc, a train of gearing mounted in each carrier, means for locking each carrier in one of two positions, in one of which the train wh ch it carries is in engagement and in the other of which the train is out of engagement with the concentric toothed rings, and means for indicating the position of each train of gear- 125 mg.

5. A coil holder and automatic tension control mechanism combined in a unit, comprising a bearing, a spindle and two sleeves all concentrically and rotatably supported in the bearing, a coil 130 holder mounted on the spindle, a brake acting on the coil holder, a spring exerting force on the brake, a screw thread on one end of the spindle, a nut working thereon controlling the spring and attached to the inner of the two 135 sleeves, an externally toothed wheel mounted on the said inner sleeve, an internally toothed wheel concentric with. the externally toothed wheel and attached to the outer of the two sleeves, said outer sleeve being constrained to rotate with the coil 14L- holder, at least two trains of gearing and means for supporting the said trains and providing for the moving into engagement with the toothed wheels of each of the said trains of which one rotates the nut at a speed several times greater than that of the outer sleeve.

6. A coil holder and automatic tension control mechanism combined in a unit comprising a coil holder, a spindle supporting the coil holder, a screw thread on one end of the spindle, a brake 150 acting on the coil holder, a spring exerting force on the brake, a sleeve on the spindle determining by its position the force exerted by the spring means for rotating the sleeve at a speed proportional to the speed of rotation of the coil holder, an enlarged end on the said sleeve having a recess therein, a two-part nut accommodated in the said recess and located axially and angularly relative to the said sleeve, a plurality of springs normally pressing the parts of said nut into engagement with the screw threaded spindle, a collar slidably positioned on the spindle and carrying two wedge pieces positioned diametrically opposite each other, a screw thread on the said enlarged end on the sleeve, and'a second nut engaging the screw thread on the sleeve, bearing against the said collar and adapted to force the 

